Die punch



Feb. 8, 1966 R. H. KING 3,

DIE PUNCH Filed May 9, 1965 awn INVENTOR. ROBERT H. KIA/G ATTOPNE VS United States Patent Gfitice 3,233,487 Patented Feb. 8, 1965 3,233,487 DIE PUNCH Robert H. King, 4260 Tonawanda Creek Road, North Tonawanda, N.Y. Filed May 9, 1963, Ser. No. 279,127 Claims. (Cl. 83-140) This invention relates to die punches and, in particular, pertains to die punches having slug ejectors associated therewith.

Die punches provided with ejector pins present a problem whenever the work-engaging face of the punch requires grinding to re-establish a good shearing edge. Since the outer end of the ejector pin projects beyond the workengaging face, the ejector pin must either be removed or pushed into and temporarily held within the body of the punch. For practical reasons, physical removal of the ejector pin, so long as it does not entail dismantling the punch, represents the least time consuming procedure and is, in general, to be preferred. However, such physical removal of the ejector pin necessitates that some releasable retaining or holding means be employed within the body of the punch; and due to the forces involved and the number of work cycles involved during the normal expected life of a punch, it is'desirable that the retaining or holding means have a life expectancy at least as great as the punch assembly. It is difficult at best, with prior art constructions, to attain a life expectancy of the retaining or holding means which is comparable to that of the punch assembly itself. Therefore, with prior art constructions, one may expect failure of the retaining means long prior to the time at which the punch will require replacement. Further, failure of the retaining means normally occurs during work operations so that the ejector pin is usually destroyed and the work damaged. It is, accordingly, of primary concern in connection with this invention to pro vide an improved form of die punch and ejector pin assembly wherein the retaining means, which permits ready removal of the ejector pin, is relieved'of any substantial wear or stresses tending to inordinately shorten its life. In particular, the retaining means of the improved assembly is not-used to transmit any slug-ejecting force, or other forces, incidental thereto.

A further problem associated with prior art retaining means is connected with the original assembly and the reassembly of the ejector pins. Specifically, it is possible with prior art devices to insufficiently engage the ejector pin with the retaining means so that the pin is accidentally released during use, resulting in destruction of the pin and damage to the workpiece. -Moreover, it is virtually impossible in theprior art to ascertain whether or not the ejector pin has been properly engaged with the retaining means. Accordingly, it is also a primary object of this invention to provide an improved die punch assembly as aforesaid wherein proper engagement of the pin with its retaining means is easily ascertained.

Essentially, both of the above objectives are attained by providing a slight amount of ejector pin lost motion between its seat on the retaining means and its engagement with the stop means which yieldably resists movement of the ejector pin into the punch body. By this arrangement, the retaining means is relieved of excessive wear and tear during use and, in addition, proper assembly and reassembly is insured since absence of the stated lost mot-ion will immediately apprise the operator that proper re-engagement has not been effected.

Other objects and advantages of the invention will appear from the description hereinbelow and the accompanying drawing wherein:

FIG. 1 is a sectional view of a die punch constructed in accordance with the present invention and illustrating the non-operating position of the parts thereof;

FIG. 2 is a sectional view illustrating the position of parts upon engagement of the die punch with a workpiece;

FIG. 3 is a view illustrating the manner in which the ejector pin may be assembled within the retaining means;

FIG. 4 is a sectional view of the ejection pin and retaining means illustrating the manner in which the retaining means deforms to permit assembly or withdrawal of the ejector pin;

FIG. 5 is a perspective view of the ejector pin; and

FIG. 6 is a perspective view of the retaining means.

With reference to FIG. 1, the punch 10 indicated therein comprises a body 12 having an enlarged head 14 at one end and which may be necked down at the work-engaging end 16 thereof corresponding to the diameter of the hole desired to be punched thereby. The collar or head 14 is received within a counterbore 18 in the plate 19 and the holder plate 20 backs up the head 14 as will be obvious from FIG. 1. The particular manner of mounting the punch is of course completely conventional and it is to be understood that a plurality of punches may be ganged on the same mounting means for effecting a desired pattern on the workpiece. v

The body 12 of the punch is provided with a bore 21 and a counterbore 22, providing a shoulder 24 at the intersection of the bore and counterbore substantially as is shown. The upper end of the body is closed by suitable plug member 26 which provides a seat against which the stop means reacts. The stop means may consist of a cylindrical abutment member 30 slidably received in the counterbore 22 and a compression spring 32 positioned in the manner indicated. The ejector pin itself, as is shown in FIG. 5, includes a shank portion 34 having a workengaging outer end 36 and having a headed inner end 38, the latter being provided by the undercut or reduced diameter portion 48 adjacent the inner end of the pin.

The retaining means as specifically shown consists of a sleeve 42 as indicated in FIG. 6, the sleeve having a body portion 44 of an axial extent exceeding that of the head portion 38 of the ejector pin shown in FIG. 5. The purpose of this construction will be set forth more particularly hereinafter. The lower end 46 of the sleeve 42 is constructed to present the annular shoulder 48 (FIG. 4) which has an internal diameter permitting free sliding of the reduced diameter portion within the constricted end 46 but which is less than the diameter of the headed portion 38 so that the headed portion 38 may rest or seat upon the annular shoulder 48 substantially as is shown in FIG. 1. The retaining means is formed preferably of synthetic resinous material such as Nylon or the like so that the constricted end 46 may deform to permit forcible withdrawal or assembly of the pin, as is shown in FIG. 4. In this particular figure, it will be noted that the constricted portion of the retaining means has been deformed radially to permit the headed end 38 to pass the shoulder 48 in the process of removing the ejector pin. To enhance this effect, the shoulder 50 (FIG. 5) on the ejector pin is preferably tapered as shown, such construction also eliminating the possible presence of sharp edges which would tend to cut or tear the constricted portion of the sleeve 42. The upper extremity 51 of the ejector pin is similarly tapered for ease in pushing the pin into place (FIG. 3) and to prevent cutting or otherwise damaging the retaining member.

It will be noted that when the ejector pin is seated upon the shoulder 48 of the retaining means, as is shown in FIG. 1, that there is a slight clearance space 52. between the inner extremity of the ejector pin and the opposing face 54 of the stop means. This clearance space is a very important aspect of the present invention inasmuch as it permits certain desirable characteristics hereinafter pointed out. In the first place, it will be noted that the abutment member 30 of the stop means directly engages the retaining means and seats the same upon the shoulder 24 in the body 12. That is to say, when the parts are in a non-operating position, the stop means. does not engage the ejector pin and thereby tend to force the same out of the retaining means. Thus, the retaining means serves only the functions of limiting the extent of downward movement of member 30, arresting return momentum'of the pin and of holding the weight of the ejector pin and, further, as is clearly shown in FIG. 2, .the retaining means does not participate in any action involving the recession of the ejector pin into the body of the die punch, or the extension of the pin partially out of the punch. Thus, there is virtually no wear and tear on the retaining means itself during operation of the device and the only time that unusual stress is applied to the retaining means is during the infrequent occasions for removal of the ejector pin for preparing the die punches for grinding their working faces. Thus, in contrast to the prior art devices wherein the retaining means thereof participates in every movement of the ejector pin, the retaining means of the present invention serves only the retaining purpose. Stating this another way, no force is transmitted through the retaining means at any time that the ejector pin holds the abutment member 30 away from the sleeve 42. This effect is achieved by virtue of the fact that the I axial extent of the reduced diameter ejector pin portion 40 is greater than the clearance space 52 pointed out in associationwith FIG. 1. If the axial extent of the portion 40 were less than the axial extent of the clearance space 52, the retaining .means would necessarily participate in movement of the ejector pin to the position shown in I FIG. 2 since it would, in this case, form an intermediate force transmitting member between the pin and the stop A further advantage achieved by the presence of the clearance space 52 is that when the ejector pin is positioned or re -engaged with the retaining means as for example as shown in FIG. 4, the operator will be positively certain when the ejector pin is properly engaged. That is, r

the operator will readily detect the presence of the lost motion permitted by the clearance space 52 if, and only if, the headed inner end 38of the ejector pin has been projected completely through the deformable portion 46 of the retaining sleeve 42. If the headed end 38 of the pin is merely being gripped by the deformable portion '46, in

chuck-like fashion, which would raise the possibility that the pin could fall out during working operations, there will be an absence of the aforesaid lost motion of the ejector pin. Thus, when using a pusher pin 60 to force the ejector pin up into the die punch body (FIG. 3) so as to push the headedend 38 through theconstricted portion 46 and hence into proper position with relation to the departing from the spirit of the invention or the scope of the following claims.

I claim: 1. In a die punch having a body provided with a shouldered bore,

stop means captive within said bore, an ejector pin projecting into said bore and having a headed inner end engageable with said stop means with the outer end of the ejector pin projecting slightly from said body, said stop means being resiliently yieldable permitting said outer end of the ejector pin to be forcibly moved into flush relation with. said body, retaining means captive within said bore and separate from said stop means, said retaining means being of deformable material and including a portion providing a seat for the headed inner end of said ejector pin to releasably retain the ejector pin against axial withdrawal from said bore while permitting axial inward movement of the ejector pin into engagement with said stop means. 2. Inthe die punch according to claim 1 wherein said retaining means is in the form of a sleeve having a constricted end, said sleeve being constructed of synthetic resinous material.

3. In a die punch having a body provided with a shouldered bore,

an ejector pin extending into said here and having a headed inner end, retaining means within said bore and normally seated upon the shoulder thereof, said retaining means having a deformable portion engaging behind said headed inner end of the ejector pin to releasably retain said ejector pin against axial withdrawal from said bore while permitting axial inward movement of said ejector pin, spring means normally urging said retaining means into its stated seated-position, and presenting a yieldable stop for said ejector pin spaced axially inwardly thereof and separate from said retaining means. 4. In a die punch having an elongate body presenting a work-engaging end and having an axial bore therethrough opening upon said work-engaging end and a counterbore extending axially from'the opposite end of the body to terminate short of said work-engaging end and, presenting a shoulder at such termination,

a retaining sleeve slidably received in said counterbore and seated upon said shoulder,

, an ejectorpin slidably received in said bore and having a portion of reduced diameter adjacent the inner end of the pin so that such inner end of the pin presents a head,

said inner endof the pin extending into said retaining sleeve and said. retaining sleeve having a deformable portion presenting a constriction of less diameter than said head, i an abutment member resting upon said retaining sleeve, anda compression spring bearing against said abutment member and normally urging said retaining sleeve 7 against said shoulder, said reduced portion of theejector pin being of greater axialextent than said deformable portion of the retaining sleeve. and said head of the ejector pin being of less axial extent than the retaining slee ve between saiddeformable portion thereof and said abutmentmember.

5. In a diepunch having an elongate body provided with a boreand a counterbore presenting a shoulder between the opposite ends of the body,

a deformable sleeve slidably received in said counterbore to seat upon said shoulder, an ejector pin received in said bore and having a headed innerv end extending into said counterbore and within said sleeve,

5 6 said sleeve being constricted at that end thereof seating pin between its seat upon said sleeve and said abutupon said shoulder to present a seat for the headed ment member. inner end of the ejector pin releasably retaining said ejector pin against axial withdrawal from said bore, References Clted by the Exammer and stop means engaging said sleeve to seat the same 5 UNITED STATES PATENTS upon Said Shoulder, 3,063,319 11/1962 Johnson 83128 said stop means including a spring and an abutment 3 019 33 2 19 2 Welbaum et 1 3 129 member, said headed inner end of the ejector pin being dimen- WILLIAM W. DYER, JR., Primary Examiner.

sioned to permit slight axial movement of the ejector 10 ANDREW JUHASZ Examiner. 

1. IN A DIE PUNCH HAVING A BODY PROVIDED WITH A SHOULDERED BORE, STOP MEANS CAPTIVE WITHIN SAID BORE, AN EJECTOR PIN PROJECTING INTO SAID BORE AND HAVING A HEADED INNER END ENGAGEABLE WITH SAID STOP MEANS WITH THE OUTER END OF THE EJECTORE PIN PROJECTING SLIGHTLY FROM SAID BODY, SAID STOP MEANS BEING RESILIENTLY YIELDABLE PERMITTING SAID OUTER END OF THE EJECTOR PIN TO BE FORCIBLY MOVED INTO FLUSH RELATION WITH SAID BODY, RETAINING MEANS CAPTIVE WITHIN SAID BORE AND SEPARATE FROM SAID STOP MEANS, SAID RETAINING MEANS BEING OF DEFORMABLE MATERIAL AND INCLUDING A PORTION PROVIDING A SEAT OF FOR THE HEADED INNER END OF SAID EJECTOR PIN TO RELEASABLY RETAIN THE EJECTOR PIN AGAINST AXIAL WITHDRAWAL FROM SAID BORE WHILE PERMITTING AXIAL INWARD MOVEMENT OF THE EJECTOR PIN INTO ENGAGEMENT WITH SAID STOP MEANS. 